Chemical composition, crystallinity, and thermal degradation of bleached and unbleached kenaf bast (Hibiscus cannabinus) pulp and nanofibers

By Mehdi Jonoobi, Jalaludin Harun, A. Shakeri, Manjusri Misra, Kristiina Oksman. BioResources, 2009

462 citations recorded by the source corpus.

Kenaf (Hibiscus cannabinus) nanofibers were isolated from unbleached and bleached pulp by a combination of chemical and mechanical treatments. The chemical methods were based on NaOH-AQ (anthraquinone) and three-stage bleaching (DEpD) processes, whereas the mechanical techniques involved refining, cryo-crushing, and high-pressure homogenization. The size and morphology of the obtained fibers were characterized by environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM), and the studies showed that the isolated nanofibers from unbleached and bleached pulp had diameters between 10-90 nm, while their length was in the micrometer range. Fourier transform infrared (FTIR) spectroscopy demonstrated that the content of lignin and hemicellulose decreased in the pulping process and that lignin was almost completely removed during bleaching. Moreover, thermogravimetric analysis (TGA) indicated that both pulp types as well as the nanofibers displayed a superior thermal stability as compared to the raw kenaf. Finally, X-ray analyses showed that the chemo-mechanical treatments altered the crystallinity of the pulp and the nanofibers: the bleached pulp had a higher crystallinity than its unbleached counterpart, and the bleached nanofibers presented the highest crystallinity of all the investigated materials.

Subfields: Biomaterials, Biomedical Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/ca24e455d40f8e094632f614ddaff64830d1515e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Biomaterials

In Biomedical Engineering

In Polymers and Plastics

Citations in the corpus

Mechanical properties of cellulose nanofiber (CNF) reinforced polylactic acid (PLA) prepared by twin screw extrusion (2010, methodology): “The details of the pulping process have been reported earlier by us [27].”
Exploration of a Chemo-Mechanical Technique for the Isolation of Nanofibrillated Cellulosic Fiber from Oil Palm Empty Fruit Bunch as a Reinforcing Agent in Composites Materials (2014, background): “In the comparison with previous studies on the isolation of cellulose nanofiber using different chemo-mechanical processes, the diameter of 5–40 nm was gained for OPEFBs cellulose nanofiber [8] and 10–70 nm for kenaf nanofibers [20].”
Morphological, thermal and mechanical characterization of okra (Abelmoschus esculentus) fibres as potential reinforcement in polymer composites (2010, background): “The two peaks observed at 1370 cm 1 and 1320 cm 1 in the spectrum indicate the bending vibration of CAH and CAO groups of the aromatic ring in polysaccharides [28].”
PREPARATION AND CHARACTERIZATION OF PVA COMPOSITES WITH CELLULOSE NANOFIBERS OBTAINED BY ULTRASONICATION (2011, background): “By a combination of chemical and mechanical treatments, Jonoobi et al. (2009) isolated nanofibers from unbleached and bleached kenaf pulp.”
Agricultural waste fibers towards sustainability and advanced utilization: a review. (2016, methodology): “There are various methods for preparing fibers from cellulose fibers such as chemical treatment (Fahma et al., 2010; Nazir et al., 2013; Siddiqui et al., 2011), mechanical treatment (Abdul Khalil et al., 2014) and chemo-mechanical treatment (Jonoobi et al., 2011; Fatah et al., 2014).”
Characteristics of cellulose nanofibers isolated from rubberwood and empty fruit bunches of oil palm using chemo-mechanical process (2011, methodology): “The high cellulose contents obtained as a result of the chemomechanical treatments we employed point to that the non-cellulosic components can be removed effectively by NaOH-AQ pulping followed by DEpD bleaching ( Jonoobi et al. 2009 ).”
Preparation of cellulose nanofibers with hydrophobic surface characteristics (2010, methodology): “The kenaf fibers were purified using sodium hydroxide, bleached and analysed as described by Jonoobi et al. (2009).”
Effects of hydrolysis conditions on the morphology, crystallinity, and thermal stability of cellulose nanocrystals extracted from kenaf bast fibers (2012, methodology): “The peaks observed in the range of 1,420–1,430 cm and 1,330–1,380 cm in all spectra were attributed to the symmetric bending of CH2 and the bending vibrations of the C–H and C–O groups of the aromatic rings in polysaccharides, respectively (Jonoobi et al. 2009).”